Carli Suspension Ford 4.5" Unchained 3.0 System | 2011–2016 F-250/F-350 Diesel 4WD

Is This for You?

• You're building a 2011–2016 Super Duty Diesel for high-speed off-road use — King 3.0" Remote Reservoir 2-Tube Bypass fronts, King 3.0" Remote Reservoir 4-Tube Bypass rears, 10.5" of front travel, and 13.0" of rear travel on a platform that requires coil bucket boring and weld-on rear mounts to install them.
• You understand this is a fabrication-level build — factory coil buckets must be cut and bored to 4.5" to clear the 3.0" bypass shock bodies, and the rear shock mounts require professional frame welding. This is not a bolt-on application at either end.
• You've read Carli's operator guidance — Carli explicitly recommends a full cab roll-cage for operators planning to utilize the full bottom-out capability of these bypass shocks. If that statement gives you pause, this is not the correct system for your build.

The Result

• 4.5" front lift / 2.5"–3.5" rear lift — 10.5" front wheel travel / 13.0" rear wheel travel.
• King 3.0" 2-Tube Bypass fronts and 4-Tube Bypass rears — position-sensitive bypass circuits deliver compliant initial stroke on-road and progressive stiffening approaching full compression.
• 17-4 stainless steel shafts, machined and polished — corrosion resistance and tensile strength above standard chrome-plated steel.

The King 3.0" bypass shock differs from a standard remote reservoir shock in one critical way: bypass tubes. A standard remote reservoir shock delivers a single damping rate across the full stroke, adjusted only by the valving stack. A bypass shock adds position-sensitive tubes that allow fluid to bypass the main piston at specific points in the stroke — the result is a soft initial stroke for on-road compliance and a progressively stiffer rate as the shock approaches full compression, preventing harsh bottom-out under high-speed impacts. The 2-tube front configuration provides two bypass circuits; the 4-tube rear provides four, giving finer damping resolution across the longer 13.0" rear travel range. The 17-4 stainless steel shafts are a precipitation-hardened stainless alloy — higher tensile strength than standard 4140 chrome-moly and significantly better corrosion resistance in high-moisture, high-salt environments. Boring the factory coil buckets to 4.5" is mandatory — the 3.0" bypass shock body diameter physically cannot clear the factory bucket geometry without it, and this step is non-reversible. The weld-on rear shock mounts (CS-FRSM-08) are required because the forces generated at 13.0" of rear travel at speed exceed what a bolt-on bracket can reliably handle structurally. Rear lift height is determined by leaf spring selection — this system does not include rear leaf springs. Fabricated radius arms (CS-FFRA-05) are sold separately and strongly recommended by Carli for proper limit strap mounting and structural integrity at this performance level.

Audit Table

Kit Contents

• 4.5" Multi-Rate Front Coil Springs (CS-FMRC-05)
• Carli Tuned King 3.0" Bypass Shock Package (CS-FUC30SPKG-45-05)
• Fabricated Coil Buckets (CS-FFCB-08)
• Fabricated Rear Shock Mounts — Weld-On (CS-FRSM-08)
• Extended Braided Stainless Brake Lines (CS-FORDBBL-11)
• Radius Arm Drop Brackets (CS-FRAD-05)
• Dominator-Spec Bump Stop Drops (CS-FBDF-05-4.5-SHORT)
• 1° Caster Shims (CS-FCASTERSHIM-4.5)

Verified Fitment

✔ 2011–2016 Ford F-250 Super Duty 4WD — Powerstroke Diesel
✔ 2011–2016 Ford F-350 Super Duty SRW 4WD — Powerstroke Diesel

✘ Does NOT fit: Ford F-250/F-350 Gas engines — spring rates and shock valving calibrated for Powerstroke diesel front axle weight
✘ Does NOT fit: Ford F-350 DRW (Dually) — front suspension geometry incompatible
✘ Does NOT fit: 2017–2026 Ford F-250/F-350 — different platform architecture; see CS-F45-D30-17 for 2017–2026
✘ Does NOT fit: 2010 and earlier Ford F-250/F-350 — different suspension geometry
✘ Does NOT fit: 2WD Super Duty models
✘ Does NOT fit: Ford F-150 — incompatible platform
✘ Does NOT fit: Ram or GM platforms

Installation Notes

• Coil Bucket Boring: Factory front coil buckets must be cut and bored to 4.5" to clear King 3.0" bypass shock bodies. Non-reversible fabrication step — professional shop required.
• Rear Shock Mounts (CS-FRSM-08): Weld-on. Requires professional frame welding — not a bolt-on application.
• Fabricated Radius Arms (CS-FFRA-05): Sold separately. Carli strongly recommends upgrading from the included radius arm drop brackets to fabricated radius arms for proper limit strap mounting and structural integrity at this performance level.
• Rear Leaf Springs: Not included. An Add-A-Pack or Full Progressive Leaf Pack must be selected separately. Rear lift height is determined by leaf selection.
• 1° caster shims (included) address caster deviation at 4.5" lift. Full front-end alignment mandatory post-installation — verify final alignment specs with installer.
• Torque all fasteners to Carli specification. Re-torque all suspension fasteners at 500-mile break-in interval.
• Professional installation required throughout — coil bucket boring and weld-on rear mounts are not DIY operations.

⚠️ LTL Freight Notice: This item ships via freight carrier on a double pallet due to size and weight (~425 lbs). Residential delivery with liftgate service is included. Freight carrier will contact you to schedule delivery.

Engineering Question: Have you confirmed your coil bucket boring plan, weld-on rear shock mount capability, fabricated radius arm (CS-FFRA-05) sourcing, and rear leaf spring selection? This is a fabrication-level build on a specific application window — 2011–2016 Ford F-250/F-350 Powerstroke Diesel 4WD SRW only. Confirm your full build plan and shop capabilities before ordering.